Fairly certain it is ionic. It's been some time since I had chemistry, but I seem to remember this having to do something with electronegativity difference. Ionic having the most difference, followed by polar covalent, nonpolar covalent.

covalent, I distinctly remeber the fact that ionic bonds don't exactly stick together...like, it is easy to break, next to hydrogen bonds. But, covalent bonds, it actually "shares" electrons, so, they are a lot stronger. mayber I am wrong, but, I doubt it.

Ok, first you need to sort out whether you are talking about a INTRAMOLECULAR or INTERMOLECULAR force of attraction.

Covalent bonds are very strong, however their INTERMOLECULAR force of attraction is weak, that is why they melt so easily.

I am not sure about which is stronger, ionic or covalent. I think that they are about the same. BUT IT DOESN'T MATTER

HOWEVER, you are probably talking about INTERMOLECULAR force of attraction, like like Zoo says here electronegativity difference. Ionic having the most difference, followed by polar covalent, nonpolar covalent